1. Technical Field
The present disclosure generally relates to apparatus, systems and methods for interventional and non-interventional treatment of refractory gout.
2. Description of Related Art
Gout is a complex form of arthritis characterized by sudden, severe attacks of pain, redness and tenderness in joints, often the joint at the base of the big toe. Symptoms of gout include sudden occurrence of pain in the large joint of the big toe, although gout can occur in feet, ankles, knees, hands and wrists. The pain is likely to be most severe within the first 12 to 24 hours after it begins with lingering joint discomfort that may last from a few days to a few weeks after the most severe pain subsides.
Gout occurs when urate crystals (hereinafter “UA crystals”) are deposited and accumulate in joints, causing the inflammation and intense pain of a gout attack. UA crystals are formed when excessive amount of uric acid accumulate in the circulatory system. UA crystals are characterized by sharp, needle-like crystalline structures that, when deposited in tendons, joints, kidneys, and other organs, results in the joint or surrounding tissue to become inflamed, swollen, tender and red.
The body produces uric acid when the digestive system breaks down purines. Purines are natural substances found in all of the body's cells, as well as in virtually all foods. A relatively high small number of foods, mostly high protein foods, contain concentrated amounts of purines such as, but not limited to, organ meats, fish, certain vegetables, game, poultry and yeast. The breakdown of the genetic material (e.g., cells) also results in the breakdown of purines contained therein, thereby forming uric acid. Normally uric acid remains dissolved in the blood circulating through the body and naturally passing through the kidneys and into urine. At normal levels, the uric acid serves as an antioxidant that helps prevent damage to blood vessel linings. As such, a healthy supply of uric acid is important for protecting blood vessels and the circulatory system.
Occasionally, the body produces too much uric acid and/or the kidneys fail to extract and/or regulate the amount of uric acid in the blood. The build-up of uric acid may be due to excessive breakdown of cells thereby exceeding the kidney's ability to extract uric acid or the build-up may be due to poor kidney function.
Gout may develop into more severe conditions such as recurrent gout, advanced gout and kidney stones. Recurrent gout results in experiencing gout symptoms several times a year. Medications may help prevent recurrent gout attacks. Advanced gout results in deposits of UA crystals under the skin in nodules called tophi. Tophi can develop in several areas such as, but not limited to, fingers, hands, feet, elbows, Achilles tendons along the back of the ankles and combinations thereof. Tophi can become swollen, tender and under extreme conditions, the tophi can rupture. UA crystals may also collect in the urinary tract resulting in the formation of kidney stones.
UA crystals may be present in the joint for a long time without causing symptoms. Infection, injury to the joint, surgery, drinking too much alcohol, or eating the wrong kinds of foods may suddenly bring on the symptoms, which include pain, tenderness, redness, warmth, and swelling of the joint. Gout attacks typically begin at night when the body temperature of the extremities lowers resulting in the crystallization of the uric acid from liquid to crystal.
During bouts of gout, the inflamed skin over the affected joint may be red, shiny, and dry, and the inflammation may be accompanied by a mild fever. The symptoms may continue for weeks, months or years. Over the course of time, attacks of gout may recur more frequently, last longer, and affect more joints. Eventually, the tophi form stone-like deposits that build up in the joints, ligaments, and tendons, which can lead to permanent joint deformity and decreased motion.
When gout remains untreated or undertreated, the intercritical periods typically become shortened, and the attacks, although sometimes less intense, can last longer. Over the long term, from about 10 to about 20 years, or less, gout can become a chronic disorder characterized by constant low-grade pain and mild or acute inflammation. Gout may eventually affect several joints, including those that may have been free of symptoms at the first appearance of the disorder.
Gout, while not curable, may be managed by medications that lower the level of uric acid in the body and/or addressing lifestyle factors that increase the risk of developing gout. The longer treatment for the underlying causes of gout is delayed, the more UA crystals are deposited in joints. Unfortunately, each episode of gout leaves deposits of UA crystals in the joints, and, in particular, in the joint of the great toe.
The present disclosure describes minimally invasive and non-invasive methods, system and apparatuses to breakdown UA crystals and/or remove from joints in the body.